Hemodialysis, the most frequently used method for treating advanced and chronic kidney failure consists of a continuous process of removing blood from a patient, cleansing the blood with a special filter mounted on a dialysis machine, and returning the cleansed blood back to the patient. During the hemodialysis procedure, a trained health-care professional will continuously monitor the arterial (pre- and/or post-pump) and venous pressure in the extracorporeal circuit. This is typically done through a tube positioned between the extracorporeal circuit and the dialysis machine. A transducer protector is an in-line sterile barrier and is recommended to be placed between the monitoring line and the dialysis machine. The main purpose of the transducer protector, if correctly used, is to prevent cross-contamination between patients. With dialysis machines, blood must be contained to the extracorporeal circuit, while the safe operation of the dialysis session depends on the ability to accurately measure the pressure in the extracorporeal circuit. The hydrophobic nature of the membrane in the transducer protector prevents fluid (e.g., blood) from passing through the membrane while allowing air to flow freely across the membrane, facilitating accurate pressure measurements. At the end of the dialysis session, the transducer protector and the extracorporeal circuit (blood tubing sets) are discarded and replaced by a new sterile set for the next dialysis sessions.
The transducer protector generally includes two components sealed around a filtering hydrophobic membrane, which acts as a sterile barrier. The two components can be any combination of a male-male, female-female and male-female connectors that attach to medical equipment. The transducer protector is believed to be essential in shielding the dialysis equipment and patients from risks of contamination by infected blood. Typical transducer protector devices are described, for example, in U.S. Pat. Nos. 5,500,003 and 5,603,792 to Guala et al.; U.S. Pat. No. 6,086,762 to Guala; U.S. Pat. No. 6,168,653 to Myers and U.S. Pat. No. 6,536,278 to Scagliarini, each of which is incorporated by reference into this application as if fully set forth herein. These references disclose transducer protectors of various configurations, but with the common features described above of a single filtering membrane between two tubular connectors.
Due to the high risk of blood contamination and incidents involving wetted/breached membranes in transducer protectors, which can occur due to fluctuation of fluid levels in the arterial and/or venous drip chamber, as well as due to changes of pressures in the extracorporeal circuit, it has become necessary to provide further protection between the pressure-sensing port of the hemodialysis machine and the extracorporeal circuit. Proposals for further protection include placing one or more redundant transducer protectors in the system and/or utilizing transducer protectors with luer extensions so that visual inspection of failure is facilitated. However, potential drawbacks to proposed solutions include, but are not limited to, the fact that they are bulky to use, they offer increased risk of non-sterile procedures, and they generally employ poor connections between the different transducer protectors.
Applicants have recognized that it would be desirable to provide a transducer protector with beneficial improvements such as greater overall protection capability, a reduction in the amount of handling and connecting required, a sustained level of connection sterility, a more precise pressure monitoring capability, and a reduction in inventory control, which provides cost savings to users.